Chang, speaking to analysts on a conference call to discuss the company's second quarter financial results, said that the market is tending to produce fewer higher volume customers and some are so large they need their own dedicated fabs. This is despite the fact that, as a foundry TSMC, has risen on its ability to serve many customers from a single line.

"I think that they are going to be larger customers, and now it makes complete sense to dedicate a whole fab to just one customer and hold that – to hold fabs in fact to just one customer," Chang was reported as saying in a Seeking Alpha transcript of the question and answer session in the conference call.

Chang said TSMC would retain the ability to serve many customers but the presence of large customers that are getting bigger means "it makes sense that we dedicate a whole fab or even more than a whole fab to just one customer."

Qualcomm is one such very large customer. It has had problems in recent months getting as much supply of 28-nm CMOS from TSMC as it would like.

Chang did not mention Qualcomm explicitly but said that Taichung, where TSMC has its Fab 15, will be the source of the majority of TSMC's 28-nm CMOS whereas Tainan, home to Fab 14, will be the source of the majority of 20-nm planar CMOS and 16-nm FinFET CMOS.